Question

I will start studying C++11 in a month and was wondering, what benefits does C++11 provide when compared to C++03?

Answer 1

If I had to nail it down to two things, I’d say that “rvalue references and variadic templates” are the most profound improvement of C++11 over C++03. Both allow you to do things that really should have been possible all along, and add enormous expressive power to the language. Finally you can have a proper unique_ptr and containers with move semantics thanks to rvalue references, and direct construction rather than copy construction thanks to both constructions playing in harmony:

template <typename ...Args>
void construct(void * p, Args &&... args)
{
    ::new (p) T(std::forward<Args>(args)...);
}

Another huge improvement is the incorporation of a memory model into the language that allows for a standardized description of concurrent execution (multi-threading).

There are tons of smaller additions that make the language more expressive, though, and allow you to do things you simply couldn’t do previously:

• brace-initialization allows you to initialize class member arrays and value-construct automatic objects.

• initializer lists allow you to initialize containers.

• a better concept of constant expressions.

• a better-specified memory layout for classes and unions, as well as fine-grained notions of “triviality” to allow optimizations as much as possible.

• lambda expressions and closures make algorithmic and functorial programming much easier and more viable.